For the past four years, Jones Lang LaSalle and the Better Buildings Partnership (BBP) have analyzed 225 commercial buildings in London and found there is little or no correlation between EPC ratings and actual energy performance. The discrepancy is often due to the overlooked role of the tenant, according to the report, “A Tale of Two Buildings,” which looks at properties with good Energy Performance Certificate (EPC) ratings compared to buildings with less impressive EPC ratings.

Occupiers’ energy demands can vary significantly, depending on the energy loadings of fitted-out space, the intensity of energy use and an occupier’s operating hours – all factors that affect the energy consumption in a building – yet are not taken into account for EPCs.

EPCs are a mandatory requirement for the sale and lease of commercial buildings to inform interested parties of the building’s energy performance.

Yet, the research finds that EPCs alone are not sufficient to deliver the UK government’s targets to ‘de-carbonise’ its built environment because EPCs focus on theoretical energy efficiency. To achieve actual reductions in energy consumption in buildings, the researchers recommend the introduction of mandatory Display Energy Certificates (DECs) for commercial property, which are based on metered energy consumption.

Also, the researchers find that collaboration between owners and occupiers is vital. In a survey conducted by the BBP, the occupier can be responsible for as much as 80-90 percent of an office portfolio’s energy consumption. In cases where occupiers obtain their own energy, their consumption data is rarely known by the owner, making it impossible to understand how efficiently these buildings are operating. The report found more efficient buildings can only be achieved through a close working relationship between the owner and occupier.